From Things of My Soul, “Creeping Mormonism,” relating the author’s surprise at seeing distinctively Mormon doctrines and beliefs, such as the idea of eternal marriage, sometimes appear in Protestant preaching or practice. It’s a two-way street, of course: many of the early Mormon doctrines had parallels in other Christian denominations of the day. Later, in one of the more unfortunate borrowings, certain LDS leaders imported Young Earth creationist theories into the LDS mainstream by relying on the arguments of George McCready Price.
I propose a trade. Mormonism will give back Young Earth Creationism if Protestants will give back eternal marriage.